[gcr]

Just as an aside, are you aware of Whalesong?

http://hashcollision.org/whalesong/

It's a Javascript VM that interprets Racket bytecode. It's complete enough to run, eg. World/Universe games or render HTDP2e pictures. Might be useful for some of what you're doing.

[nickmain]

Thanks - yes I was aware.

I thought that Whalesong was a Javascript code generator rather than a VM ?

Unfortunately JS performance on iOS rules that out for our purposes.